In this introductory chapter we provide an overview of criminological research into intergenerational transmission of criminal behaviour that currently is, and has been, conducted both internationally and in the Netherlands. The most important findings of these studies are also discussed. Next, possible explanations are discussed for intergenerational transmission of crime in general, and more particularly for families that are involved in more serious and organized crime. Moreover, possible ways in which intergenerational transmission of crime can be prevented are discussed. Finally, we give some directions for future research on this topic and will introduce the contributions to this special issue.

The Netherlands are considered as an important hub for the illicit trade in species of endangered birds protected by the CITES convention. In this article the authors analyze five substantial criminal cases from three different perspectives. First, from a criminal business perspective, the cases illustrate that logistics vary from relatively simple to highly complex, but always require in-depth knowledge of the animals as well as regulations, to be able to keep the birds alive to make a profit, and to smuggle them to the Netherlands, respectively. Second, from a network perspective, it is clear that those who are involved in the illicit trade – suppliers, traders and customers – are part of a closed and often long-lasting group of people who know the trade. Finally, from a green criminological perspective, the authors conclude that harms of the illicit trade in protected birds are mentioned only to a limited extent in court rulings, contrary to what one might expect based on social construction theories of criminalization and sentencing.

This article on intergenerational transmission of crime in families is based on a study of seven families of which at least one member held a key position in an organized crime group. The authors retrieved information on at least three generations (preceding and succeeding this key member’s generation) to investigate whether transmissions occurred, and if so, how these might be explained. Throughout the generations the majority of family members indeed have criminal records. However, it seems to be less easy to transfer criminal leadership in organized crime from one generation to the next. Leading a criminal group seems to demand qualities that are not transferred easily. Successful successors appear to be able to establish their own networks within the deviant subcultures from which they stem. This also explains the persistence of criminal behavior: both men and women select their friends and partners from these closed communities and seem to prefer for their social and love relationships those who have already developed substantial criminal track records. Organized crime families in North Brabant took advantage of criminal opportunities that were presented to them over the years. Particularly XTC production, starting in the 1990s, allowed them to step up their criminal activities from the local to the global level. In addition, they may have capitalized on a moral economy with sentiments of subordination present in the province of North Brabant, dating back to the seventeenth century, which resulted in a more reserved attitude towards authorities than in other parts of the Netherlands. Finally, law enforcement agencies have been generally slow to respond to developments in criminal opportunities that benefited these seven families.

In the past decades, organised crime internationalised rapidly as a result of increasing mobility and ‘open’ borders. At the same time developments in information and communication technology have led to modernisation of existing types of crime and the introduction of novel ones. Finally, criminals have benefited from increasingly diversified migration streams. In the Netherlands and Belgium, organised crime appeared on the agenda in the 1990s. For a long time emphasis was on ‘trade crimes’ i.e. trafficking in drugs and humans, as well as human smuggling, followed by the production of synthetic drugs and cannabis. More recently the Low Countries are confronted by more visible manifestations of organised crime, for example rapid growth of outlaw motorcycle gangs. Criminals also try to utilise their capital to invest in businesses and real estate and to influence local politics.

Comparing an organized crime group to an ‘enterprise’ or ‘firm’ and its key persons to ‘entrepreneurs’ is only a small step to viewing its illegal activities as a business process. Yet, it took until the early 1990s before criminologists started to study the logistics of specific illegal activities. Since then, the Dutch police have adapted to thinking of organized crime in terms of criminal business processes and to erecting barriers (preferably insurmountable ones) to specific steps in these processes. Firstly, the police analyze logistical processes to find weak spots that can be targeted to hinder illegal activities most effectively, either through investigative action or by means of preventive measures. Secondly, law enforcement agencies consider such an analytical approach an attractive tool to explore the viability of involving other public or private parties in setting up barriers. The Dutch investigation authorities have used this concept successfully in the case of ecstasy production, by aiming at the small number of suppliers of particular chemicals and hardware. As regards large-scale (and indoor) cannabis cultivation, however, the approach is less fruitful, because there are no explicitly ‘vulnerable’ stages in the cultivation process. Furthermore, some of the intended barriers can be deemed rather intrusive, such as a plan to persuade banks to withdraw a mortgage if the police discover a cannabis nursery in a person's private home. This raises the question to what extent the police and the judiciary may call in other parties to help them put up barriers to illegal activities, instead of using the conventional tool of criminal investigation.

Considerable differences in tax and excise levels since the Belgium independence in 1830 gave rise to large scale smuggling between the Dutch border province Noord-Brabant en Belgium. The smuggling history can be divided in six periods. Salt was the most important contraband in the last quarter of the nineteenth century. During the First World War a lot of food was smuggled from the Netherlands to Belgium. During the crisis years in the 1930s unemployed people used to supplement their scarce income through smuggling. Belgian tobacco was the most important contraband during the Second World War. After the war ten thousands of Dutch occasional smugglers illegally fetched consumer and luxury goods in Belgium. In the 1950s and 1960s millions of kilo's of Dutch butter were smuggled to Belgium. The smuggling business gradually came into the hands of professional criminal gangs. In the second half of the 1960s the smugglers switched to the illegal distilling of alcohol. Many years later these would evolve into labs for the production of chemical drugs.

The social network approach is gaining influence among criminologists studying organized crime and terrorism. The theoretical concept, however, still needs further elaboration. To this end, concepts developed within the field of economic sociology could provide a substantial contribution. Economic sociologists have, among other things, focused on the role of social networks with regard to the completion of economic transactions. They regard mutual trust built through personal relations as an essential part of economic transactions, particularly if these imply certain risks for the parties involved. In other words, before transactions materialize, the parties must first be able to establish trustworthy personal relations. Based on these ideas, Spapens introduced in 2006 the theoretical concept of the criminal macro network, being a social network consisting of individuals able and willing to engage in illegal activities. The capital of each member of the criminal network consists, on the one hand, of his links, defined as information relations, within the network. On the other hand, a person’s position is determined by personal knowledge and skills. It is assumed that executing an actual illegal activity – e.g. drug production, trafficking human beings, bank robbery – requires cooperation between a subset of members of the criminal network, the criminal group.An extensive study of xtc production in the south of the Netherlands between 1996 and 2004 revealed the existence of a ‘xtc network’ consisting of individuals interconnected by social relations. The macro network proved to be relatively stable over time. The composition of the criminal groups, however, changed regularly. This was not only explained by shifting business opportunities, but also by the efforts of the police and the Public Prosecution Service leading to convictions and the dismantling of criminal groups. Better knowledge of the functioning of the criminal macro network can provide valuable contributions to criminological understanding of organized crime. These insights are of course also of great practical importance for law enforcement agencies.